IMHO, goat skins won't fit on congas, even Aspire. It only can fit a bongo macho, if you like the sound. (As I said, IMHO).
Why don't you try the above link ? (or another one)
If you want some spare rims, it's a good idea. You can order some in a music shop, or here : http://artdrum.com/LP_RIMS_ASPIRE_CONGA_DRUM_10_&_11_RIMS.htm
. Since it's the USA, you'll have to pay the shipping...
You can also try to find a metal craftsman in your neighbourhood (e.g.
a blacksmith or a worker of wrought iron) who can make you some rims.
It's all up to you now.